Filipe Brandenburger wrote:
Hi,
On Thu, Jun 4, 2009 at 08:37, Theo Band theo.band@greenpeak.com wrote:
When I use top, I see that running processes use 245% instead of 100%. If I use gkrellm, I just see one core being used 100%. There are all single threaded programs, so it's not that more cores are being used.
Are you sure?
You can type "H" in top to show separate threads, that way it would show up if you have more than one thread running in one of those programs
Yes I'm quite sure. For instance cpuburn on two machines, the only difference is hardware (two versus four cores). The H option does not show more threads:
Machine a (dual core Centos5 64 bit) Intel(R) Core(TM)2 Duo CPU E8400 2.6.18-128.1.6.el5 #1 SMP Wed Apr 1 09:10:25 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux
top - 09:26:00 up 62 days, 21:43, 1 user, load average: 0.30, 0.16, 0.17 Tasks: 120 total, 3 running, 117 sleeping, 0 stopped, 0 zombie Cpu(s): 50.0%us, 0.2%sy, 0.0%ni, 49.8%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 4050728k total, 2448800k used, 1601928k free, 405860k buffers Swap: 3538936k total, 22172k used, 3516764k free, 1762448k cached
PID USER PR NI VIRT RES SWAP SHR S %CPU %MEM TIME+ COMMAND 16916 thba 25 0 2068 988 1080 308 R 100.2 0.0 0:11.48 cpuburn-in
Machine b (quad core Centos5 64 bit) Intel(R) Core(TM) i7 CPU 940 @ 2.93GHz 2.6.18-128.1.6.el5 #1 SMP Wed Apr 1 09:10:25 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux
top - 09:28:24 up 25 days, 40 min, 2 users, load average: 1.44, 1.83, 1.83 Tasks: 165 total, 3 running, 162 sleeping, 0 stopped, 0 zombie Cpu(s): 25.1%us, 0.5%sy, 25.0%ni, 49.4%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 6097924k total, 4366540k used, 1731384k free, 152248k buffers Swap: 4194296k total, 112k used, 4194184k free, 3322344k cached
PID USER PR NI VIRT RES SWAP SHR S %CPU %MEM TIME+ COMMAND 13873 thba 25 0 2068 988 1080 308 R 243.8 0.0 0:26.97 cpuburn-in
The total cpu reported is about correct (for the second machine two jobs ran, one cpuburn-in=25% and one other with nice15=25%). It's just the individual process on this quad core machine that's way off. When I build the machine a couple of months ago, I did benchmarks and used top as well. It did show "normal" results, most of the time 100% for a process and sometimes a little more. So I guess an update in the mean time has changed something.
Theo